Comparação entre métodos de estocagem de DNA extraído de amostras de sangue, sêmen e pêlos e entre técnicas de extração Comparison between storage methods of DNA extracted from blood, semen and hair and between the techniques of extraction

DNA samples of six bovines obtained from three tissues (blood, semen and hair) were extracted using two different techniques. After the extraction procedures the samples were divided in six fractions. Three were stored at -20° C and three at 4° C. Every three months one sample of each tissue/extraction procedure was analyzed in spectrophotometer, to determine the quantity of the DNA and the extract was amplified using the primer RM 29. No differences in the DNA quantity or in the level of protein contamination among the three periods of analyses were observed. All the DNA extracted by quick extraction technique showed good amplification patterns during the nine months, meaning that this technique can be used in laboratory routine instead of the permanent extraction technique. The extract obtained from blood, using the permanent extraction technique, showed the higher quantity of DNA with the smaller index of protein contamination. The high quantity of protein contamination found in the semen samples preserved in egg yolk demanded modifications in both extraction techniques. After that the results were positive, showing good amplification patterns